1. Field of the Invention
The invention relates to a rubber blend, in particular for the inner liner of pneumatic vehicle tires. The invention furthermore relates to pneumatic vehicle tires having an inner liner which is based on such a rubber blend.
2. Discussion of Background Information
In tubeless pneumatic vehicle tires, an inner liner which is as impermeable to air as possible and arranged radially on the inside, also referred to as inner core or inner plate, ensures that the air pumped into the tire does not escape. Escape of air must be counteracted since the escape leads to a reduced pressure in tires which greatly impairs the stability of the tire. Furthermore, the inner liner protects the carcass from the entrance of air and moisture by diffusion. The strength members of the carcass and/or of the belt can be damaged by air and moisture. To ensure that the inner liner remains air-tight, it must also have good resistance to tearing and fatigue so that no tears which impair the air tightness form during driving.
Chlorobutyl rubber or bromobutyl rubber, occasionally as a blend with natural rubber, are usually used as rubbers for the inner liner. These rubber types have a low gas permeability. By metering in bulky fillers having little or no activity, the air tightness can be further increased. These fillers include, for example carbon black of type N 660 and chalk.
EP 0 832 927 B1 discloses a rubber blend for inner liners of pneumatic vehicle tires which contains nonactivated silica as a filler. The use of layered silicate for inner liners of pneumatic vehicle tires is described in U.S. Pat. No. 5,576,372.
By metering in inactive fillers, such as chalk or other fillers having a layer structure or lamellar structure, the air tightness of the inner liner can be further improved but the tearing and fatigue properties are simultaneously adversely affected thereby.